Measuring one or more characteristics of a construction material is important for insuring integrity of a given building project. For example, in the road construction industry, it is important to determine the density of the underlying soil surface before, during, and after layment of asphalt or concrete, and additionally for determining the density of the asphalt or concrete during the laying process. If the density is less than a desired amount, additional rolling or compacting of the soil, asphalt or concrete may be required.
There are many methods for determining the density of the road surface, however, the most efficient and accurate method for determining density has been by using a nuclear source and counting or analyzing the nuclear radiation with some type of nuclear detector. Using a nuclear source has the disadvantage of subjecting use of nuclear sources to regulatory oversight.
Conventional nuclear-based density gauges may have various disadvantages associated therewith, including shielding required to limit accidental or inadvertent exposure to the nuclear source. Accordingly, new and improved nuclear density gauges are needed.